Novel synthesis of ZnO supported on 1D-MWCNT nanocomposites enhancing electrochemical energy storage performance of asymmetric supercapacitor

Abstract

High-power flexible supercapacitor electrodes were created by mixing ZnO nanorods with MWCNTs. The inclusion of MWCNTs boosted the electrical conductivity of carbon nanotubes, whereas ZnO/MWCNTs decoration increased their energy storage capacity. The impact of the metal (ZnO/MWCNTs) ratio on the overall electrochemical performance of the supercapacitor was studied by varying the C concentration. ZnO increases the specific capacitance by providing Faradaic redox processes. ZnO/MWCNT nanotubes enhanced electrolyte transport into the electrode, hence boosting electrochemical activity. The nanotubes also boosted the charge transfer rate within the composite electrode, which improved its overall electrochemical performance. The designed asymmetric supercapacitor cell possesses Faradic properties and a specific capacity of 215.62 Fg⁻¹, with 93.2% capacity retention after 3000 GCD cycles. Long-term cycle performance is maintained by the composite structure, which inhibits ZnO nanoparticle aggregation. Furthermore, the cell possesses a specific energy of 13.86 Wh kg⁻¹ and a high specific power of 5298 W kg⁻¹. The extraordinary electrochemical performance of the ZnO/MWCNTs electrode demonstrates that it is an appropriate negative electrode material for asymmetric supercapacitors. These findings suggest that the ZnO/MWCNTs NC is a suitable material for supercapacitor applications.